1#!/usr/bin/env python
2
3
4#############################################################################
5##
6## Copyright (C) 2013 Riverbank Computing Limited
7## Copyright (C) 2010 Hans-Peter Jansen <hpj@urpla.net>.
8## Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
9## All rights reserved.
10##
11## This file is part of the examples of PyQt.
12##
13## $QT_BEGIN_LICENSE:BSD$
14## You may use this file under the terms of the BSD license as follows:
15##
16## "Redistribution and use in source and binary forms, with or without
17## modification, are permitted provided that the following conditions are
18## met:
19##   * Redistributions of source code must retain the above copyright
20##     notice, this list of conditions and the following disclaimer.
21##   * Redistributions in binary form must reproduce the above copyright
22##     notice, this list of conditions and the following disclaimer in
23##     the documentation and/or other materials provided with the
24##     distribution.
25##   * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor
26##     the names of its contributors may be used to endorse or promote
27##     products derived from this software without specific prior written
28##     permission.
29##
30## THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
31## "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
32## LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
33## A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
34## OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
35## SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
36## LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
37## DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
38## THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
39## (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
40## OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
41## $QT_END_LICENSE$
42##
43#############################################################################
44
45
46from PyQt5.QtCore import (pyqtSignal, QBuffer, QByteArray, QFile, QIODevice,
47        QMimeData, Qt)
48from PyQt5.QtGui import QDrag, QIcon, QImage, QPainter, QPixmap
49from PyQt5.QtWidgets import (QApplication, QGridLayout, QLabel, QPushButton,
50        QScrollArea, QWidget)
51from PyQt5.QtSvg import QSvgWidget
52
53import delayedencoding_rc
54
55
56class MimeData(QMimeData):
57
58    dataRequested = pyqtSignal(str)
59
60    def formats(self):
61        formats = QMimeData.formats(self)
62        formats.append('image/png')
63
64        return formats
65
66    def retrieveData(self, mimeType, qvtype):
67        self.dataRequested.emit(mimeType)
68
69        return QMimeData.retrieveData(self, mimeType, qvtype)
70
71
72class SourceWidget(QWidget):
73    def __init__(self, parent=None):
74        super(SourceWidget, self).__init__(parent)
75
76        self.mimeData = None
77
78        imageFile = QFile(':/images/example.svg')
79        imageFile.open(QIODevice.ReadOnly)
80        self.imageData = imageFile.readAll()
81        imageFile.close()
82
83        imageArea = QScrollArea()
84        self.imageLabel = QSvgWidget()
85        self.imageLabel.renderer().load(self.imageData)
86        imageArea.setWidget(self.imageLabel)
87
88        instructTopLabel = QLabel("This is an SVG drawing:")
89        instructBottomLabel = QLabel("Drag the icon to copy the drawing as a PNG file:")
90        dragIcon = QPushButton("Export")
91        dragIcon.setIcon(QIcon(':/images/drag.png'))
92        dragIcon.pressed.connect(self.startDrag)
93
94        layout = QGridLayout()
95        layout.addWidget(instructTopLabel, 0, 0, 1, 2)
96        layout.addWidget(imageArea, 1, 0, 2, 2)
97        layout.addWidget(instructBottomLabel, 3, 0)
98        layout.addWidget(dragIcon, 3, 1)
99        self.setLayout(layout)
100        self.setWindowTitle("Delayed Encoding")
101
102    def createData(self, mimeType):
103        if mimeType != 'image/png':
104            return
105
106        image = QImage(self.imageLabel.size(), QImage.Format_RGB32)
107        painter = QPainter()
108        painter.begin(image)
109        self.imageLabel.renderer().render(painter)
110        painter.end()
111
112        data = QByteArray()
113        buffer = QBuffer(data)
114        buffer.open(QIODevice.WriteOnly)
115        image.save(buffer, 'PNG')
116        buffer.close()
117        self.mimeData.setData('image/png', data)
118
119    def startDrag(self):
120        self.mimeData = MimeData()
121        self.mimeData.dataRequested.connect(self.createData, Qt.DirectConnection)
122
123        drag = QDrag(self)
124        drag.setMimeData(self.mimeData)
125        drag.setPixmap(QPixmap(':/images/drag.png'))
126        drag.exec_(Qt.CopyAction)
127
128
129if __name__ == '__main__':
130
131    import sys
132
133    app = QApplication(sys.argv)
134    window = SourceWidget()
135    window.show()
136    sys.exit(app.exec_())
137